1. Technical Field
The invention relates to an electronic switch for usage in automatic test equipment (ATE) and other precision measurement equipment.
2. Related Art
In ATE for testing of mixed signal devices there is a demand for sharing expensive system instrument resources, particularly high power and precision voltage and current sources, across multiple pins of a device under test (DUT).
Traditional ATE uses mechanical or reed relays to fulfil this requirement. The drawback of this approach is the limited lifetime of relays. Not only that the lifetime of relays at defined load is physically limited, since there are unpredictable malfunctions in the DUT, the relays will be exposed to unpredictable combinations of voltage and current during their lifecycle. The relay approach in traditional ATE is therefore critical from the system reliability point of view. In addition to the described reliability issue, mechanical relays need a relatively long time to operate. This time significantly limits test throughput and drives up testing costs.
There exist a lot of approaches to replace mechanical or reed relays by electronic switches. Unfortunately, all known electronic switches have drawbacks compared to mechanical ones. For high precision measurements, especially the leakage current through an open switch limits possible measurement accuracy and a significant capacitive coupling of the open switch leads to signal crosstalk that impacts dynamic measurements.